Former team-mate Joe Cole once said Chelsea always play ten percent better with John Terry in the starting XI.

At 35 years of age and approaching retirement, that still appears to be true; the Blues are yet to lose a Premier League fixture with their Captain, Leader, Legend at the heart of defence this season, whilst his absence through injury saw the west Londoners endure debasing defeats to Premier League title rivals Arsenal and Liverpool.

Gary Cahill and David Luiz have both proved capable partners to the former England man over the years, but inevitably failed to fill the void of leadership and organisation his injury left behind. Chelsea struggled not only defensively but as a collective without their skipper barking orders from the back.

 

So with Terry now declared fit by the most reputable of sources, manager Antonio Conte, the logical assumption is that he’ll be thrown straight into the starting XI to face Manchester United on Sunday - a match that would see the veteran defender face-off against the manager he owes much of his success to, a certain Jose Mourinho.

Yet, Terry’s sideline stint, and Chelsea’s subsequent struggles in his absence, forced Conte into a tactical rethink. In the dying embers of a 3-0 defeat to Arsenal, the Italian switched to the three-man defensive system that paved the way for his three Serie A titles with Juventus, not to mention overachievement (at least in terms of performances) with an ordinary Italy side at Euro 2016.

Conte has stuck with it ever since, and results have been impressive. The 3-4-3 line-up at the KCOM Stadium swept aside Hull City with ease in a 2-0 win and the same XI, with the exception of Pedro coming in for Willian, went one better against reigning champions Leicester City at home last weekend. Crisis averted - it appears the world does keep on turning without Terry after all.

Nonetheless, the solution for Sunday still seems simple; if 3-4-3 is getting the best out of Chelsea in Terry’s absence, surely his re-introduction would propel them to even higher levels of domination - all the better, just in time to face United. Cesar Azpilicueta isn’t even a centre-half, making him the obvious candidate to make way for the Chelsea captain.

But there’s always a gap between the theory and the reality, the reality in this instance being a far better balanced back three without Terry included. Of course, not every utilisation of the same system has to follow the exact same pattern, yet it’s hard to place Terry in any of the three positions without disrupting the formula Cahill, Luiz and Azpilicueta have successfully kindled.

Terry’s made a career out of dominating the left central position, suggesting that should be his role in the back three. But the wider centre-back berths require speed, to firstly cover the central man and secondly close down wingers who make it past the wingback. Terry’s spent his career avoiding one-on-one situations and he’s more vulnerable in them now than ever before, but they’re an inevitable part of that role.

So the central slot, surely, where Terry would be protected by defenders either side of him and can simply hold the line as per usual? Yet, that would diminish (or eradicate completely) arguably the best asset in Chelsea’s three-man defence - David Luiz.

Defensive question marks still linger over the Brazil international, but his ability to come into midfield has been invaluable during the two wins the 3-4-3 formation has provided. Indeed, the combined 180 minutes has seen Luiz contribute one created chance, seven accurate long balls and 85 passes.

Terry’s no fool on the ball either - in fact, it was one of his greatest attributes in his younger years - but at the age of 35, he can’t be expected to shimmy into the engine room and distribute in the same way. For starters, he doesn’t have the recovery speed to re-join the backline if a pass goes astray.

That could be incredibly important for Chelsea on Sunday, facing a United side that will have three in midfield and surrender the lion’s share of possession to the home team. Whilst Luiz could well go onto control the match as the spare man, especially if the Red Devils sit deep, Terry would have to settle for being the last line of defence. In other words, that spare man would be ten or twenty yards further back than he should be.

But the implications span further than this weekend. If Conte plans to continue using the 3-4-3 formation, it could quickly become a very difficult, potentially final, season for Chelsea’s iconic defender. Indeed, rather than injuries or an irreversible downturn in form, it could be Conte’s tactical reshuffle that brings an unspectacular, bench-warming end to Terry's illustrious career.